Obesity prevention efforts are increasingly focused on early childhood. Substantial evidence indicates that household routines for children that support having family meals and obtaining adequate sleep can help prevent obesity. Emerging evidence suggests that responsive parenting and children's self-regulation may also reduce risk for obesity. However, no population-based studies have investigated how household routines, parental responsiveness, and child self-regulation work together to influence future weight status. It is unknown whether household routines are more effective in preventing obesity when they are implemented in the context of parental responsiveness or if the impact of routines on obesity prevention is due to children's greater self- regulation. The objective of this applicationis to use epidemiologic analyses of existing data from two cohort studies-the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), and the NICHD Study of Early Child Care and Youth Development (SECCYD)-to investigate the extent to which parental responsiveness modifies the impact of household routines on children's risk for obesity and whether self-regulation offers an explanatory mechanism. The central hypothesis is that household routines around sleep and meals, when practiced in the context of parental responsiveness, will reduce children's risk for obesity by increasing their capacity for self- regulation. The rationale for this research is to provide the basis for improving childhood obesity prevention strategies by addressing the emotional context in which household routines are implemented and identifying self-regulation as a potential mechanism. The proposal has two specific aims: 1) to determine the extent to which parental responsiveness in early childhood modifies the impact of household routines to protect against later obesity, and 2) to identify self-regulation as a mechanism explaining how routines and responsiveness are associated with obesity. Both ECLS-B and SECCYD include structured observations of parental responsiveness and children's self-regulation, serial measurements of children's height and weight, and assessment of household routines in early childhood. The proposed epidemiologic analyses will focus on obesity at age 5.5 years in ECLS-B and adolescent obesity in SECCYD, with assessment of routines, responsiveness, and self-regulation at age 24 months in ECLS-B and 54 months in SECCYD. The approach is innovative because it uses creative and cost-efficient analyses of existing data, informed by developmental science, to provide the basis for new and more effective obesity prevention interventions in early childhood. The proposed research is significant because the knowledge gained can be expected to stimulate innovation in efforts to prevent childhood obesity. Obesity interventions, informed by the proposed research, that increase household routines, responsive parenting, and children's self-regulation can be expected to have additional positive impacts on children's behavior, cognitive development, and social-emotional functioning. Childhood obesity prevention interventions that offer non-obesity benefits may effectively motivate and engage parents.